--- title: Explained: AdBlue in a Diesel Tank The Broadway canonical: https://www.petrolinadieselcar.co.uk/adblue-in-diesel/the-broadway-buckinghamshire/ location: The Broadway county: Buckinghamshire latitude: 51.706150 longitude: -0.612520 service: AdBlue in a Diesel Tank updated: 2026-10-11 --- # The Broadway: How Does AdBlue End Up in a Diesel Tank, and How Do You Prevent It? If AdBlue is already in your diesel tank, stop reading for a moment: leave the motor and your ignition off and phone 0333 366 0103. Caught before the engine runs, it is generally a drain and a thorough flush, done where your car is around The Broadway. The remainder of this page covers why it takes place and how to make sure it doesn't — handy if you are reading ahead of time. ## Two fillers, two tanks: AdBlue in a diesel motor No single fluid but two: that is what plenty of modern diesels near The Broadway and Pednormead End run, with diesel for your motor. AdBlue's own tank keeps it, and from there it goes to the exhaust, and there spraying cleans the gas. Separate tanks, separate fillers. On a lot of vehicles the two sit side by side under the same flap; on others the AdBlue filler is in the boot or under the bonnet. The diesel side is filled at the pump all the time. A driver who has to stop and think where it goes usually tops up the AdBlue side, from a bottle, and much less frequently. That gap is where the error lives. ## How does AdBlue in your diesel tank take place around The Broadway? Seldom is it carelessness: usually three things line up. On a driveway off The Broadway before work, or in the car park at The Tavern on the way home: that is where the rushed top-up takes place. What is the reason for the rush? As AdBlue runs low the car tells you, and if it's gone, limp mode kicks in. Then the car is unfamiliar. A hire car, a new car or a company car puts the fillers where your last one didn't, and your hand gets to for the cap it would have used on the old one. No part halts the tip after it has started, because a bottle with a spout goes into a diesel filler as easily as an AdBlue one. The bottle fits. It takes seconds, be it in Chesham or right in the centre of The Broadway. ## Which filler is for AdBlue, and which for diesel? Before you tip anything, whether on a driveway in Waterside or a forecourt in The Broadway, check these. They take a couple of seconds. - Colour and lettering: an AdBlue cap is regularly blue, or says "AdBlue", where a diesel cap normally doesn't. Go by the cap, not where it sits. - The size. On many vehicles the AdBlue filler neck is the smaller of the two. - The flap. Look inside your fuel flap for a label. Plenty of motors say there which fuel goes where. - The handbook shows which it lives when your filler is not next to the diesel cap: your boot, or under the bonnet. - Ask the person who drove it last — before you leave, not when the light comes on — if you collect a hire or company car from somewhere like the car park at Amersham. ## AdBlue top-ups that never reach the diesel tank Wherever around Buckinghamshire the light comes on, this is a routine for that day. - Not in a rush on the side of High Street, not on a slope, not with the engine running: park then switch off properly. - Find the AdBlue filler and read the cap. Say "AdBlue" out loud as you unscrew it. It sounds daft and it works. - The two behind one flap? So confirm the cap on your diesel filler is still shut ahead of lifting the bottle. - Gently is best, through the bottle's own spout, till it's full or the bottle is empty. - Close the cap, and check again — making sure the diesel filler remained shut throughout. Only then, start your car. Stop there if you find, at step two or three, that you have already poured into the diesel side. Leave out step five altogether. ## AdBlue in your diesel tank already, around The Broadway? Short list, then. Top of it: the motor stays unstarted. Leave the ignition off too, since on plenty of diesels it by itself starts the fuel pump. Don't top up with diesel to thin it: AdBlue does not mix with diesel, it sinks to the bottom of that tank, where the fuel is drawn from. Ask the attendants to help roll your car away from the pump if you are on a forecourt — the BP, the Esso or anywhere else. On your own drive around The Broadway? Then your car remains where it is. When the engine has run already, pull over safely then turn the car off. On the M25, under 10 miles from The Broadway, that means the next junction. Mileage counts — a short hop across The Broadway is a smaller job than driving under 15 miles towards St Albans — so say about how far it went. ## When our engineers arrive around The Broadway, what happens? The van reaches the car wherever it stopped — your own driveway, near United Reformed Church Chesham, or by Thomas Harding Junior School. Both the work and the price rest on three answers — what liquid, which quantity, and if it's run — so our engineers ask. That quote comes over the phone, before any van leaves. Draining that tank comes next, then a full flush of the fuel system. Much more than with petrol, it counts here: the crystals build up, some metals are attacked, and nothing clears away on its own, however long it is left. A test is at the end: before that, fresh diesel goes in, and your filter is cleaned or changed as needed. We don't go until it has been started and is running smoothly. Most jobs are done in roughly half an hour once our engineers get there, as long as your motor hasn't run — and the pumps our technicians use are safe on a busy forecourt and quiet after dark beside a house. Paying happens on the day, not upfront, and you are given the documents your insurer wants: an engineer's report and a VAT invoice. Before we get there, have a look at your policy; many carry cover for misfuelling. ## About The Broadway itself The Broadway is a locality in Buckinghamshire, situated in a riverside setting with an elevation of around 101 metres. The Broadway lies near several other places, including Chesham, Newtown, and Griffitts Yard, and is approximately 12 miles from St Albans. The Broadway is characterized by a high proportion of flat housing, reflecting its urban nature. The Broadway is also relatively close to London, at a distance of around 25 miles. ## AdBlue drains across Buckinghamshire, The Broadway included The Broadway is a small village, and our vans that cover it also work the places near it, Newtown and Griffitts Yard among them, across the HP postcode area. A postcode starting HP5 1 gets the van to you fastest. The vehicle remains put. The drain happens on the spot, be it a drive, a street by Chesham Public Library, or a layby on the way to Lowndes Park. Guessing won't help at the back of Chesham Town Council, on a border, or somewhere awkward to pin down; phone and ask. ## For The Broadway motorists, the short version Tip no AdBlue until you have read the cap. If AdBlue has gone in the diesel tank anyway, leave the vehicle off and phone 0333 366 0103. Petrol in Diesel clears it where it stands, anywhere around Buckinghamshire.